Left 4 Dead 2 is a FPS that deeply relies on communication and teamwork with your allies. Taking place in a world full of Rabid Hordes.
You and your gang having to face against it with guns, melee weapons, and much more.

Left 4 Dead 2 came out in 2009 on Steam and Xbox 360.

I will mention the Items you shouldn't worry about.

Rake
Shovel
MP5
SG-552
Scout Rifle
AWP
CS Knife
Workshop

In Left 4 Dead 2, Your goal is to make it to the end of the Campaign.
You have Guns, Melee weapons and much more stuff to use against the hordes of infected.
And you also got three teammates by your side to help you out.

A campaign will have at Two to Five chapters. (Mainly four)
Each campaign has their own set-ups and chapters.
The best ones to start is Dead Center or No Mercy.

Characters do not have different stats from each other. So don't worry about getting the worst!

You can play with a Controller on PC if you wish.

WASD/Upper Joystick to move

Mouse/Lower Joystick to look around

Space/A to jump

Scroll Wheel/Numberkeys/Y/DPad to switch through items

CTRL/Upper Joystick to crouch

Left Click/Left Trigger to Shoot/Swing Melee

Right Click/Right Trigger to Shove Enemies Back

E/X to interact with certain Items

F/Up on DPad to Toggle Flashlight

TAB/Select to check ScoreBoard

ESC/Pause to Pause

There are lots of weapons in Left 4 Dead 2 to use, from Assault Rifles to Grenade Launchers.

Primary Guns

Assault Rifles
AK-47: The AK-47 Deals the most damage, but the most bullet spread. (Tip: Its first shot is always laser accurate, use it to your advantage.)

M16 (Assault Rifle): The M16 has the highest fire rate, however the least damage.

SCAR-H (Combat Rifle): The SCAR-H is the most accurate, however it is Three Burst which can sometimes cause bullet waste.

SG-552: The SG-552 is pretty different from all the others, it including a scope that can be used by pressing on the scroll wheel (default key bind), however using the scope decreases your fire rate.

Sub-machines

Uzi (SMG): The UZI has high fire rate, However low damage.

MAC10 (Silenced SMG): The MAC10 is similar to the Uzi, however its suppressed which makes it harder for zombies to hear your shots.

MP5: The MP5 deals the most damage, however least accurate and has the most bullet spread.

Shotguns

Remington 870 (Pump Shotgun): The Remington 870 shoot 10 pellets per shot, deals 25 damage per pellet max damage being 250. (Tip: Shoving after shooting can skip the pump animation.)

Chrome Shotgun: The Chrome Shotgun is also pump-action but is a little different from the Remington, shooting 8 pellets instead of 10 and its max damage being 248. (Tip: Shoving after shooting can skip the pump animation.)

Tactical Shotgun: The Tactical Shotgun is a Semi-Auto Shotgun, shooting 11 pellets per shot and 23 damage per pellet max being 253/

Combat Shotgun: The Combat Shotgun is a Semi-Auto Shotgun, shooting 9 pellets per shot and its max damage being 252.

Sniper Rifles

Ruger Mini-14 (Hunting Rifle): The Ruger Mini-14 is a Semi-Auto Sniper Rifle can deal good damage against enemies. (Tips: You can scope in with this by pressing on the mouse wheel or pressing on the lower joystick on your controller, Be sure to stay a good distant away from the infected when using this, that way you can't get distracted by close enemies, The Ruger Mini-14 can pierce through multiple Infected.)

Military Rifle: The Military Rifle is a Semi-Auto Sniper Rifle that holds double the Ruger Mini-14's magazine being 30. (Tips: You can scope in with this by pressing on the mouse wheel or pressing on the lower joystick on your controller, You can shoot through walls with this, so you can kill enemies that are possibly on the other side of that wall your facing.)

Scout Rifle: The Scout Rifle is a Bolt-Action Sniper Rifle, dealing more damage than the Ruger Mini-14 and Military Rifle, However its Bolt-Action could punish you if you mess up a shot.

AWP: The AWP is a Bolt-Action Sniper Rifle, dealing the most damage out of all Sniper Rifles, however having a slight slower bolt pull than the Scout Rifle. (Tip: Laser Sights don't matter for this weapon, its accuracy already being maxed out.)

Special Weapons

M60 (LMG): The M60 is a bad-ass LMG that's mainly found in The Passing campaign. It dealing crazy damage. However it only having one magazine and can't be refilled at ammo packs.

Grenade Launcher: The Grenade Launcher is what is sounds like! Be careful when using this. It can deal damage to allies and can't be refilled at ammo packs. It can also stun special infected. Cannot stun Chargers or Tanks however.


Secondary Guns

P220 (Pistol): The P220 is a Pistol with minimal damage, and bullet spread. You will always spawn with this weapon at the beginning of a campaign. (Tip: This weapon has infinite ammo.)

Akimbo Pistols: Akimbo'd Pistols double your magazine. However less accuracy. (Tip: This weapon has infinite ammo.)

Deagle (Magnum): The Deagle deals more damage than the other two, however having less ammo. (Tips: This weapon can penetrate through more than one common, which can lead to more than one kill with a single bullet, This weapon has infinite ammo.)

Melee Weapons

Frying Pan (Bad Range, can stun groups of Infected)
Baton/Nightstick(Quickest swing speed, least range)
Cricket Bat(Reskin of Baseball Bat)
Baseball Bat (blunt version of Katana)
Crowbar (Good area damage, slow swing speed)
Golf Club(Good Range)
Guitar (Good range)
Shovel (Can stun a group of Infected)

These weapons can cut Smoker Tongues.
Katana (Good damage, good swing speed)
Machete (Good swing speed)
Fireaxe(Slowest swing speed, most area damage)
Rake (Bad straight range)
CS Knife/Knife (Bad swing range, only one direction)

Chainsaw: The Chainsaw is different from all the others.
The chainsaw will run on limited gas and cannot be refilled.
Dealing great damage upon the revved victims.

Incendiary Ammo Box: The Incendiary Ammo Box can be placed and used to upgrade your weapons ammo magazine to use Fire Bullets. They can't be applied to Pistols.

Explosive Ammo Box: The Explosive Ammo Box: can be placed and used to upgrade your weapons ammo magazine to use Explosive Bullets, Be careful though. They deal good damage to teammates. They can't be applied to Pistols.

Laser Sight Box: Laser Sight Boxes can be found rarely, they apply Laser Sights to your Primary, Increasing its accuracy. They can't be applied to Pistols.

Molotov Cocktails: Molotovs are used to create temporary fire spreads. Anything that walks into the fire will take damage.

Pipebombs: Pipebombs will make a ticking noise, making infected run after it and killing all victims after a couple of seconds.

Bile Jar: Bile jars can be used to mark enemies or have infected attack biled victim.

First Aid Kit: First Aid Kits can be used to heal yourself or teammates. They will heal you at usually 80 permanent health. but will heal less depending on your health's condition.

Defibrillator: Defibrillators can be used to bring a dead player back, giving them 50 permanent health.

Pain pills: Pain pills give 40 temporary health.

Adrenaline: Adrenaline gives 20 temporary health and also increasing your speed, do tasks quicker, infinite shoves and immune to speed decreases temporarily.

Always be sure to share your medical supplies with your allies if they have an empty slot.

Teamwork and Chatting with Teammates is an important part of Left 4 Dead 2, It can help get through campaigns a lot and might even help you make new friends.

Never Get A Head: Getting a head from your group is a terrible idea. It's basically a Death Wish as a Jockey/Hunter/Smoker/Charger could get you good and easily!

Giving Medicals: You can give medical items to your teammates by clicking right click/right trigger (default keybind), or hold right click/right trigger if you wanna use your medkit on them.

Call out important items/dangers: Sometimes you'll be the only one to notice certain things around you, Like for example. a Walking Witch right in the middle of a door frame. Or a hearing/seeing a Tank around the corner. Or finding a Grenade Launcher, Tell them important things so they can be prepared for whats a head!

Be nice and respectful: Kindness is the route to go within your team. Gives you a good reputation. However being a bad fellow can end up in you getting vote kicked or team killed... So don't be a bad sport.

Uncommon Infected can be found in certain campaigns, each campaign having their own unique ones.

Dead Center
Hazmat Suit: Immune to Fire, will also drop Bile Jars sometimes.
Jimmy Gibbs: Has 3000 health and will cover your screen with oil upon hitting you.

The Passing
Fallen Survivor: Will drop loot upon killing.

Dark Carnival
Clown: Makes honk noise upon them running or you shoving them which will attract other commons towards them.

Swamp Fever
Mudmen: Will crawl and cover your screen with mud upon hitting you.

Hard Rain:
Worker: Immune to Pipebomb tickings.

The Parish:
Riot: Bulletproof unless shot in the back, will also drop Baton/Nightsticks sometimes.

No Mercy:
Hazmat Suit: Immune to Fire, will also drop Bile Jars sometimes.
Worker: Immune to Pipebomb tickings.

Dead Air:
Worker: Immune to Pipebomb tickings.

Special Infected have their own unique quirks.

Boomer, The Fat Guy: The Boomer can throw up on survivors, marking them for Commons and Uncommons attack, The Boomer can also explode upon being killed and being close enough will mark you and can also stun you and other infected including other Specials for a bit if close enough.

Hunter, The Parkour Emo: The Hunter can be pin survivors down and rip flesh out from their bodies. The pinned survivor cannot save themselves. (Tips: Shove and they try pinning you it could save you from getting pinned, Hunters jumping from high areas onto a survivor will deal damage.)

Spitter, The Single Freak: The Spitter can spit acid at survivors, dealing damage if they stand over it. Killing Spitters will also unleash a bit of acid where they died. The longer you stand in the acid the more damage you will take from it so be quick.

Charger, The Football MVP: The Charger can Charge at survivors, The pummeled survivor cannot save themselves. (Tips: Chargers can hit more than one survivor in one charge, Watch where you are! Chargers can charge you off areas which can lead into instant death.)

Smoker, The nicotine addict: The Smoker can constrict survivors from good distances. Constricted survivors can't save themselves. (Tips: Smokers can pull you off a ledge, forcing you to cling onto it.)

Jockey, "rreeee": The Jockey can ride survivors and drag the victim away. (Tips: Shove as they try to ride you it could save you, Try using WASD in the opposite direction the Jockey is moving to resist their influence.)

Witch, Nick's EX Wife: There are Two types, Walking and Sitting Witches.

Sitting Witches will spawn anywhere. Being close to them for to long will provoke the Witch. (Tip: Kill your flashlight as that will also provoke the witch.)

Walking Withes will spawn anywhere and will stroll around slowly, Being around them for to long will provoke the Witch, Touching them will immediately provoke the Witch. But thankfully they are immune to flashlights.
They will chase after the survivor that provoked them and slash at them for an instant incapacitation/kill.

(Tip: Both types of Witches can be stunned if they are shot in the Head with a Sniper Rifle, so if they are in your way use the Snipers to your advantage if you happen to have one.)

Tank, Just built different: The Tank is a buff beast that can knock survivors and throw stuff (Tips: If you have a Molotov try to throw it at the Tank to cause endless fire damage to it. Try to not get cornered... If the Tank corners you, you could be done for... The Tank can knock stuff into Survivors, stuff like Cars, Dumpsters and Cargo. Which will lead into and Instant Incapacitation/Kill)

If your health ends up reaching 0 you will fall down on the ground on your back.
You will have 300 Temporary Health and you can't walk.
You will lose 3 Temporary Heath each second.
However you can still use a pistol or Deagle (Magnum) while down.

A Teammate has you help you get back on your feet.

If you reach 0 while down you die.
If you are helped you are given 30 Temporary Health.

Going down again will go the same.
However being picked back up again will put you on "Last Stand"

Last Stand will make your screen black and white and play a heartbeat sound. If you go down again... You die.

Using a Medkit will reset the System.

If you die, you end up spectating your alive teammates.
But don't worry you are not dead forever. There are three ways to come back.

Rescue Closets, Defibrillators or if your team makes it to the next safe room.

If everyone dies or goes down the chapter will be reset back to the safe room.

Ledge Clings: count as a Down, but instead of You're health going down to 30 Temporary your health will go down proportionate to how long you were clinging.
You will also not be able to use your pistol.
You will not cling to ledges if you are the last survivor alive.

Environmental Items can be found across the map, some being hazardous.

Jerry cans: You can pick them up. Shooting them will cause a temporary fire spread.

Firework box: You can pick them up. Shooting them will cause a temporary fire spread.

Rescue Closets: Rescue Closets are used to Revive Dead Survivors after being dead long enough.

Propane: You can pick them up. Shooting them will cause a explosion.

Grounded Sentry Guns: They are found at mainly finales of campaigns (No Mercy, Swamp Fever and The Parish for example). They deal great damage and slow Tanks down. However they can overheat so don't use them to much.

Explosive barrel: Shooting them will cause a explosion and will cause a temporary fire spread.

Car Alarms: Car Alarms can be commonly found around the City-Like Areas. (No Mercy, The Parish, Dark Carnival for example) Hitting them, Shooting them or Throwing something at them will trigger it and start a horde.

Air Canister: You can pick them up. Shooting them will cause a explosion.

Gnome: You can pick them up. The Gnome is obtainable by beating the Carnival Game at Dark Carnival Chapter Two, It does absolutely nothing. Unless you want the "Guardin' Gnome" Achievement.

Cola: You can pick them up. Used to give to Whitaker.

There's a bunch of game modes to pick from! Endless fun perhaps?

Single Player: Play a Campaign with Online Play restricted entirely

Split-Screen: Play with a buddy around you! You can only play with one buddy.

Campaign: Play a campaign with Players around the world.

Realism: Realism is a little different from the others.
You can't respawn until the next chapter once you're dead (unless a defib is used.
Headshots one hit kill, anywhere else will do less damage.
Items no longer have a outline.
Survivors will no longer have an outline.
No red outline when a Special infected attacks a teammate.
Witches kill in one hit.

Mutation: Mutation contains multiple options that can change gameplay a good bit depending on what you pick. For example, Last Man on Earth makes you alone for the whole game. No commons and Only Special Infected.

Versus: Versus is where 4 players go against 4 other players. 4 controlling Survivors and the other 4 controlling the Special Infected. Team with the most points win. Points are given based on how far the Survivors go. Defibrillators will give penalty however.

Realism VS: Realism and Versus slapped into one.

Survival: In Survival your goal is to survive for as long as you can. Around the map lies supplies you and your team can use. You spawn with Dual Pistols in Survival.

Survival VS: Survival and Versus slapped into one.

Scavenge: In Scavenge your team goes again another team of four that controls the Special Infected. Your goal is to collect as Many Gas Cans as you can. by pouring them into red outlined area you'll get points and the Infected has to try and stop you. Team with the most points win.

Want more content? Then take a look at the Steam Workshop!

You can change and add a lot with it!

Add new campaigns
Replace weapon models
Replace survivors or infected!
Much more!